When digital processor based electronic equipment is powered up, it generally goes through a series of self checks variously known as Power-Up Self Test (POST) or Start-up Built-in Test (SBIT). These self-checks often include procedures that detect faults that could become latent failures or cause malfunctions of a system.
Running a POST or SBIT takes a certain amount of time. During a normal power-up, the amount of time is generally not critical because the system is generally not in a state in which operation of the equipment is critical. However, if the equipment is in an operating state and a power interruption occurs, it may be desirable to return the equipment to an operating state as quickly as possible to avoid unsafe operating conditions. The effects of waiting for a self check to run under such conditions range from inconvenient to disastrous. This would be particularly true, for example, if the digital processors at issue are controlling a moving vehicle such as an aircraft. It is therefore desirable to provide a power system having components that do not perform their normal power up self tests after certain types of power interruptions.